1. Field of the Invention
The present invention relates to an apparatus and method for interfacing between an audio/visual (A/V) system and a portable device. More particularly, the present invention relates to an apparatus and method for interfacing between and A/V system and a digital data recording and/or reproducing apparatus for transmission and reception of a control signal and a digital stream therebetween.
2. Description of the Related Art
The use of portable multimedia devices, such as MP3 players, has recently begun to increase. Accordingly, there is a need for a technology that is capable of reproducing a multimedia file which is stored in a portable device, on an A/V device, such as a personal computer (PC) and a car audio system, or a technology for controlling the portable device. A user may experience greater benefits if an audio signal of a portable device is listened through an amplifier (AUX) of a non-portable device or with a digital sound field (DSP) effect, or if a file stored on an MP3 player is reproduced and the operation is controlled through a car audio while the user drives a car. So far, there has been no technology capable of controlling the operation of a portable multimedia file recording and/or reproducing apparatus in an A/V system and a linking stream.
FIG. 1 is a block diagram illustrating an example in which conventional multimedia recording and/or reproducing devices 114 through 118 operating as universal serial bus (USB) portable devices are connected to an A/V system 100.
Referring to FIG. 1, the conventional A/V system 100 comprises a key input unit 101, a control unit 102, an MPEG codec 104, a DVD module 106, a video output unit 108, an audio output unit 110, and a USB connection unit 112. If multimedia recording and/or reproducing devices, such as a hard disk drive (HDD) 114, a digital camera 116, and a wireless terminal 118, are connected to the USB connection unit 112, these devices are recognized as portable storage devices, and the control unit 102 generates a list of files that can be reproduced, and outputs the list through the output unit 108 so that a user can recognize multimedia files that can be output.
If the user desires to have a specific file reproduced, the file is read from the device 114, 116 or 118, the file is decoded in the MPEG codec 104, and then, the decoded signal is transmitted to the video output unit 108 and the audio output unit 110.
Recently, a variety of multimedia content files have become available for purchase as content files. Many content files are sold and protected by digital rights management (DRM). Reproduction of the content to which the DRM technology is applied is limited so that only one device can reproduce the content. According to the conventional technology, a file bought to be reproduced in the devices 114 through 118 cannot be reproduced in the A/V system 100 even though the devices 114 through 118 are connected to the A/V system 100 through the USB connection unit 112.
The A/V system 100 should have a codec capable of decoding the formats to successfully support content files with a variety of formats. That is, in the case of a content file in a format that can be reproduced in the external devices 114 through 118 but cannot be supported by the MPEG codec unit 104, the content file cannot be reproduced in the A/V system 100.
FIG. 2 is a block diagram illustrating data of a portable device 220 being reproduced in a non-portable device 210 according to a conventional technology.
Referring to FIG. 2, in order to listen to an audio signal of the portable device 220 through an amplifier or the DSP effect of the non-portable device 210, the analog output of the portable device 220 is connected to an amplifier (AUX) of the non-portable device 210. This configuration is inconvenient because the non-portable device 210 and the portable device 220 should be operated separately. Also, since only an analog audio signal can be transmitted from the portable device 220, the quality of sound is degraded.
FIG. 3 is a block diagram illustrating a portable device 220 that is controlled from a non-portable device 210 according to a conventional technology.
Referring to FIG. 3, in order to control the portable device 220, an operation command transmitted by the non-portable device 210 is converted in a separate control box 300 and transferred to the portable device 220. An RS232C connection between each module is used. However, this configuration has a drawback in that it requires a separate device.
FIG. 4 is a block diagram illustrating data of a portable device 410 being reproduced in a car audio/visual (A/V) system 420 according to a conventional technology.
This is a method extending the use of the conventional car A/V system, by reproducing a multimedia file stored in the portable device 410 in a car A/V system 420. This allows a user to experience greater benefits if multimedia data with a variety of formats is listened through an amplifier (AUX) or with a DSP effect of the car A/V system 420 that is a non-portable device, or if a file stored in an MP3 player is reproduced and the operation is controlled through the car A/V system while the user drives the car.
Referring to FIG. 4, an analog output of the portable device 410 is connected to an amplifier (AUX) of the car A/V system 420. This configuration is inconvenient because the car A/V system 420 and the portable device 410 should be operated separately. That is, when a file stored on an MP3 player is listened through a car audio system, volume is controlled through the car audio system, and song selection is inconveniently performed in the MP3 player. Furthermore, due to battery life restrictions of the portable device, it is impossible to use for an unrestricted period time.
Accordingly, there is a need for an improved system and method for interfacing between an audio/visual (A/V) system and a digital data recording and/or reproducing apparatus for transmission and reception of a control signal and a digital stream.